I refer to the letter by Zahid Abbas Religion is never wrong, only believers in which he says:

'Islam is the oldest religion in the world, founded by Adam, and it was reborn with Abraham and a second time with Muhammad. Between Abraham and Muhammad, Hinduism, Buddhism, Judaism and Christianity emerged in this order. Then Sikhism emerged after the time of Muhammad. These are the six world religions.'

Although I am not a religious scholar, I take opposition to Zahid 's statement that Islam is the oldest religion.

Abraham is the patriarch of the Jews. And if you look at the following dates, one can see that Prophet Mohammed, whose teachings are recorded in the Quran and form the basis of Islam, was alive between circa 570 and 632.

Even if Zahid considers Abraham as the patriarch of Muslims, he still doesn't get the dates right as there is archeological evidence (as far back as 3000BCE [Before Common Era]) from the Punjab and Indus Valley suggesting that Hinduism is indeed the world's oldest religion. The Vedas were written in 1500BCE. Moses recorded Torah in 1400BCE.

And Islam, Hinduism Buddhism, Judaism and Christianity didn't originate in that order.

Zoroastrianism (sometimes called world's oldest prophetic religion) was started by Zarathustra while Jainism and Buddhism started in India in the eighth century and 483BCE respectively. Christianity began with the teaching of Jesus Christ in 30CE (Common Era).

Although I understand the perceived notion of religious scholars to say that their respective religion is the oldest and therefore the most purest, this doesn't always hold well if not corroborated with evidence.

B.C. (Before Christ)

circa. 2000? Abraham, founder of Judaism, is alive.

c. 13th century Moses, Hebrew lawgiver, is alive

c. 1100 - c. 500 The Vedas, sacred texts of the Hindus, are compiled.

604 Traditional birth date of Lao-tzu, founder of Taoism.

588 Traditional birth date of Zoroaster's revelation.

c. 563 - c. 483 Buddha, founder of Buddhism, is alive.

551 - 479 Confucius, founder of Confucianism, is alive.

c. 540 - c. 468 Mahavira, founder of the Jains, is alive.

c. 200 The Bhagavad Gita, important Hindu text, is written.

6 or 4 - c. A.D. 30 Jesus of Nazareth, founder of Christianity, is alive.

A.D. (Anno Domini)

33? The crucifixion and death of Jesus Christ.

64? Peter, disciple of Jesus and, according to tradition, first bishop of Rome, dies.

c. 70 - c. 100 First four books of the New Testament - Matthew, Mark, Luke, and John - are written.

5th century Two Buddhist sects - Zen and Pure Land (or Amidism) - are established.

c. 570 - 632 Muhammad the Prophet - whose teachings, recorded in the Quran, form the basis of Islam - is alive.

622 Muhammad flees persecution in Mecca and settles in Yathrib (later Medina); the first day of the lunar year in which this event, known as the Hegira, takes place marks the start of the Muslim era.

936 Traditional date of the arrival from Iran of the first Parsis (followers of Zoroastrianism) in India.